[Clinical characteristics and reoperation of symptomatic adjacent segment degeneration postoperation of lumbar fusion].

Objective: To evaluate the clinical characteristics and reoperation of symptomatic adjacent segment degeneration postoperation of lumbar fusion.

Methods: In the study, 28 cases of symptomatic adjacent segment degeneration postoperation of lumbar fusion from May 2007 to April 2012 were retrospectively reviewed,with an average age of (64.3±8.7) years. The mean period between reoperation and primary fusion surgery was (47.5±30.8) months. Symptomatic adjacent segment degeneration located in cephalic segments in 12 cases, in caudal segments in 14 cases and in both segments in 2 cases. Of all the 28 patients, 12 suffered from lumbar stenosis, other 13 from lumbar disc herniation and still other 3 from both lumbar stenosis and disc herniation, of whom 11 were together with segment instability. Localization diagnoses of 19 cases were clear and other 9 received diagnostic nerve root block. The cases were divided into two groups by the type of reoperation,of which 8 cases were in adjacent degenerative segment nonfusion group and the other 20 cases in adjacent degenerative segment fusion group. The clinical results were assessed by lumbar pain visual analog score (VAS) and lower limber pain VAS,lumbar Japanese Orthopedic Association (JOA) score and Prolo functional score before operation and in the final follow-up.

Results: In adjacent degenerative segment nonfusion group, the average operation time was (86.3±17.1) min and average blood volume was (125.0 ±37.8) mL of reoperation and 1 case with dural injury; and in adjacent degenerative segment fusion group, the average operation time was (201.6 ±71.0) min and average blood volume was (313.6±218.9) mL of revision surgery and 4 cases with dural injury. The average follow-up period was 25.5 months. In the final follow-up,lumbar pain VAS,lower limber pain VAS,lumbar JOA score and Prolo functional score of adjacent degenerative segment nonfusion group were 2.4±1.2, 2.8±1.4,23.5±4.2 and 8.2±1.5,which were better than preoperation 5.5±2.9, 6.8±2.5, 13.7±5.2 and 4.3±2.1, P<0.001; lumbar pain VAS, lower limber pain VAS,lumbar JOA score and Prolo functional score of adjacent degenerative segment nonfusion group were 3.3±1.9, 3.1±1.2, 22.2±4.4 and 7.7±1.6, which were better than preoperation 5.4±2.7, 7.0±2.4, 13.0±5.6 and 3.9±1.9, P<0.001.In the final follow up, lumbar pain VAS of adjacent degenerative segment nonfusion group was better than that adjacent degenerative segment fusion group(P=0.028).

Conclusion: Symptomatic adjacent segment degeneration postoperation of lumbar fusion is difficult for diagnosis and treatment. Appropriate reoperation could get the good results.